Fix VS issue with unhandled exception on secondary threads (#103425)

* Fix VS issue with unhandled exception on secondary threads When "just my code" is disabled, unhandled exceptions on secondary threads cause the VS to stop without any stack trace shown. This is similar to the recently fixed problem that was happening with user unhandled exception treatment. The exception is rethrown as native exception after leaving the last managed frame and it propagates to the `ManagedThreadBase_DispatchOuter` where it is caught. The debugger gets notified from there, but all of the managed stack frames are gone at that point, so the debugger cannot show them. The fix is to report exception on a secondary thread as unhandled earlier, right in the SfiNext where we report it for the primary threads. The secondary thread is different in having the DebuggerU2MCatchHandlerFrame on stack while in the primary thread case, there is no explicit frame. Close #103385 * Modify the check for DebuggerU2MCatchHandlerFrame We need to check that it is also the topmost frame --------- Co-authored-by: Jan Kotas <[email protected]>
dotnet · Jun 15, 2024 · 69a475a · 69a475a
1 parent ae71602
commit 69a475a
Showing 1 changed file with 9 additions and 5 deletions.
diff --git a/src/coreclr/vm/exceptionhandling.cpp b/src/coreclr/vm/exceptionhandling.cpp
@@ -8213,6 +8213,11 @@ void FailFastIfCorruptingStateException(ExInfo *pExInfo)
     }
 }
 
+static bool IsTopmostDebuggerU2MCatchHandlerFrame(Frame *pFrame)
+{
+    return (pFrame->GetVTablePtr() == DebuggerU2MCatchHandlerFrame::GetMethodFrameVPtr()) && (pFrame->PtrNextFrame() == FRAME_TOP);
+}
+
 static void NotifyExceptionPassStarted(StackFrameIterator *pThis, Thread *pThread, ExInfo *pExInfo)
 {
     if (pExInfo->m_passNumber == 1)
@@ -8289,7 +8294,7 @@ static void NotifyExceptionPassStarted(StackFrameIterator *pThis, Thread *pThrea
                     pFrame = pFrame->PtrNextFrame();
                     _ASSERTE(pFrame != FRAME_TOP);
                 }
-                if ((pFrame->GetVTablePtr() == FuncEvalFrame::GetMethodFrameVPtr()) || (pFrame->GetVTablePtr() == DebuggerU2MCatchHandlerFrame::GetMethodFrameVPtr()))
+                if ((pFrame->GetVTablePtr() == FuncEvalFrame::GetMethodFrameVPtr()) || IsTopmostDebuggerU2MCatchHandlerFrame(pFrame))
                 {
                     EEToDebuggerExceptionInterfaceWrapper::NotifyOfCHFFilter((EXCEPTION_POINTERS *)&pExInfo->m_ptrs, pFrame);
                 }
@@ -8518,9 +8523,6 @@ extern "C" bool QCALLTYPE SfiNext(StackFrameIterator* pThis, uint* uExCollideCla
         }
         else
         {
-            // TODO-NewEH: Currently there is one case of internal VM->managed transitions: COMToCLRDispatchHelperWithStack
-            // Either add handling here as well or rewrite it in C#, so that CallDescrWorker is the only path that
-            // needs to be handled here.
             size_t CallDescrWorkerInternalReturnAddress = (size_t)CallDescrWorkerInternal + CallDescrWorkerInternalReturnAddressOffset;
             if (GetIP(pThis->m_crawl.GetRegisterSet()->pCallerContext) == CallDescrWorkerInternalReturnAddress)
             {
@@ -8544,7 +8546,9 @@ extern "C" bool QCALLTYPE SfiNext(StackFrameIterator* pThis, uint* uExCollideCla
             _ASSERTE(retVal != SWA_FAILED);
             _ASSERTE(pThis->GetFrameState() != StackFrameIterator::SFITER_SKIPPED_FRAME_FUNCTION);
 
-            if (pThis->m_crawl.GetFrame() == FRAME_TOP)
+            pFrame = pThis->m_crawl.GetFrame();
+            // Check if there are any further managed frames on the stack, if not, the exception is unhandled.
+            if ((pFrame == FRAME_TOP) || IsTopmostDebuggerU2MCatchHandlerFrame(pFrame))
             {
                 if (pTopExInfo->m_passNumber == 1)
                 {